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The intramuscular connective tissue plays a critical role in maintaining the structural integrity of the muscle and in providing mechanical support. The current study investigates age-related changes that may contribute to passive stiffness and functional impairment of skeletal muscles. Variations in the extracellular matrix in human quadriceps femoris muscles in 10 young men, 12 elderly males and 16 elderly females, and in the hindlimb muscles of 6 week old, 8 month old and 2 year old C57BL/6J male mice, were evaluated. Picrosirius red, Alcian blue and Weigert Van Gieson stainings were performed to evaluate collagen, glycosamynoglycans and elastic fibers. Immunohistochemistry analyses were carried out to assess collagen I, collagen III and hyaluronan. The percentage area of collagen was significantly higher with aging (p < 0.01 in humans, p < 0.001 in mice), mainly due to an increase in collagen I, with no differences in collagen III (p > 0.05). The percentage area of elastic fibers in the perimysium was significantly lower (p < 0.01) in elderly men, together with a significant decrease in hyaluronan content both in humans and in mice. No significant differences were detected according to gender. The accumulation of collagen I and the lower levels of hyaluronan and elastic fibers with aging could cause a stiffening of the muscles and a reduction of their adaptability. [ABSTRACT FROM AUTHOR]

The quality of welded joints is affected by microstructure heterogeneity of the weld seam. In this work, the microstructure homogenization of 2A14 aluminum alloy weld seam was achieved by adding ultrasonic irradiation in the metal-inert gas welding (U-MIG). Compared with the traditional MIG, the width and penetration of the weld seam in the U-MIG increased by 1 mm and 1.7 mm, respectively. Ultrasonic cavitation was the main reason for the microstructure homogenization of the weld seam. The columnar grains near the fusion line in the conventional MIG were completely transformed into the equiaxed grains under the action of ultrasonic irradiation. The size of equiaxed grains was more refined than that of the initial columnar grains. [ABSTRACT FROM AUTHOR]

Extracellular matrix (ECM) of intramuscular connective tissue (IMCT) play critical role not only in maintaining integrity of muscle, but also in providing mechanical properties and local signals to modulate muscle cell fusion and regeneration. The aim of this study was to investigate whether the contents of ECM of IMCT change with aging. Age-related changes of ECM in human quadriceps femoris were compared in 10 young men (37.5±9.0y), 12 elderly men (79.0±12.4y) patients with traumatic fracture (Studio 3027P/AO/13). Agerelated ECM alterations in mice hindlimb were compared in 6-weeks puberty (group A); 8-months middle age (group B) and 2-years old (group C) C57BL/6J male mice. Hematoxylin Eosin, Picrosirius-red, the collagen type I (COLI), III (COLIII) antibody, and biotinylated hyaluronan binding protein (HABP) immunohistochemistry staining were used to evaluate the morphology, collagen content, COLI, COLIII and HA both in human and mice muscle cross-section. Alcian Blue, Weigert Van Gieson staining were used to evaluate the glycosaminoglycans and elastic fiber components in human male specimens. Age-related alterations of HA concentrations were evaluated both in human and mice specimens using Purple-Jelley HA assay. The collagen contents in IMCT were also significantly increased in mice with aging, above all due to an increase in COLI both in the human (P =0.001) and mice specimens, while there were no significantly differences in COLIII. In addition, the area percentage of elastic fibers in perimysium was significantly lower (P<0.01) in the elderly men group. The HA content was significantly decreased in the elderly men compare to the young men (P=0.04). In addition, the amount of HA in mouse hindlimb muscle was also significantly decreased with health aging. The accumulation of collagen content and decreased HA in ECM of IMCT, the decreased relative elastic fibers in perimysium may cause the IMCT stiffer and reduce its' adaptability, changing gliding of the IMCT and influence the function of muscle fibers. These alterations of ECM in IMCT properly can partly explain the peripheral mechanisms of the decline of age-related locomotor ability. [ABSTRACT FROM AUTHOR]

The ultrasonic intensity was changed in different ultrasonic radiator heights (URH). Compared with conventional GMAW, the pulsed ultrasonic assisted gas metal arc welding (PU-GMAW) was an effective and newly-developed aluminum alloy welding method, because of its rapid droplet transfer and deep weld penetration. In PU-GMAW, the penetration and width of weld was increased due to the increase of the arc energy. When the URH was 20 mm and 22 mm, the droplet transfer mode of projected transfer changed to the mixed transition, which included projected transfer and short-circuiting transfer. The hardness of welded joint increased with the effect of pulsed ultrasonic, and the columnar crystal zone width of weld seam decreased. Ultrasonic radiation force was a determinant factor in arc compression and droplet transfer acceleration. The microstructure improvement in the PU-GMAW was caused by ultrasonic vibration and ultrasonic cavitation. [ABSTRACT FROM AUTHOR]

Graphical abstract The influences of frequency on short-circuiting transfer characteristics in PU-GMAW process were investigated by the welding electric signal and high-speed video images. The droplet transfer processes of adding pulsed ultrasonic were more stable than that of conventional GMAW. The peak current and droplet cycle in GMAW was improved obviously by adding pulsed ultrasonic. The dimensionless parameters (γ and Δ γ) were carried out to quantify the effect of ultrasonic on droplet transfer behavior in PU-GMAW. Abstract Addition pulsed ultrasound in GAMW process, which is described as the pulsed ultrasound wave assisted GMAW (PU-GMAW), has become a new method to control the droplet transfer process. The effect of frequency on short-circuiting transfer characteristics in the PU-GMAW process was investigated. The short-circuiting transfer processes were analyzed via welding electric signal and high-speed video images. The results showed that the droplet transfer processes of the PU-GMAW with the frequency of 20Hz and 50Hz were more stable than that of the conventional GMAW and U-GMAW. The PU-GMAW at the frequency of 50Hz obtained the minimum peak current and the minimum droplet transfer cycle. The droplet size and arc shape in the PU-GMAW also had a similar conclusion. The middle electromagnetic forces of the U-GMAW and the PU-GMAW were greater than that of the GMAW. The electromagnetic force of the PU-GMAW was bigger than that of the U-GMAW when the r was less than 1.75mm. Additionally, the electromagnetic force of U-GMAW was bigger than that of PU-GMAW when the r increased to more than 1.75mm. The greater the electromagnetic force increment, the stronger the effect of ultrasound on the electromagnetic force. Therefore, the effect of ultrasound on the electromagnetic force was the biggest in the middle of the arc. Meanwhile, the influence of pulsed ultrasound on the electromagnetic force was stronger compared with the U-GMAW. [ABSTRACT FROM AUTHOR]

An entirely new change-rule of an arc shape was found in the pulsed ultrasonic assisted tungsten-electrode inert gas welding process (PU-TIG), i.e., the arc shape had an obvious characteristic of periodic changes under the actions of a pulsed ultrasonic wave in PU-TIG. However, periodic changes of the arc shape were different between the arc white bright zone and the arc dark bright zone. The varying process of the arc shape was that the arc shape went through from expansion to contraction and re-expansion. Meanwhile, the constantly changing acoustic radiation force and electromagnetic force were the main cause of the periodic change of the arc shape in the PU-TIG welding process. [ABSTRACT FROM AUTHOR]

In narrow gap gas metal arc welding (GMAW), it is useful to understand the arc behaviors to ensure the weld quality. Arc behaviors are strongly affected by the shielding gas composition. In this study, a three-component shielding gas mixture was used in tandem narrow gap pulsed GMAW, and the effect of its composition on arc behaviors and weld formation were investigated. The shielding gas included argon, carbon dioxide, and helium. The arc behaviors and electrical characteristics were recorded by a high-speed camera and an electrical signal acquisition system. The results show that the arc behaviors in different shielding gas are different. The arc expands and the arc length decreases with the increase of CO content or helium content. The arc is the widest when the shielding gas is 80%Ar10%CO10%He. The weld shape was observed, and it was found that the weld width increases first and then decreases with increasing of the CO content. When the helium content is below 15%, the weld width increases as the helium content increases, but when the helium is 15%, the weld width drops due to the decrease of arc length. When the helium content is above 15%, the weld width continues to increase as the helium content increases. The largest weld width can be obtained in 80%Ar10%CO10%He. [ABSTRACT FROM AUTHOR]

Arthritis pain affects people's long-term health, and recent studies have demonstrated that transient receptor potential vanilloid type 1 (TRPV1) plays a crucial role in arthritis pain. In addition, Pre-clinical evidence indicated that botulinum toxin type A (BoNT/A) has antinociceptive effect. The present study investigated the causality between the antinociceptive effects of BoNT/A and the expression of TRPV1 in dorsal root ganglion (DRG) in rats with adjuvant-arthritis pain. The results showed that BoNT/A significantly reduced adjuvant-arthritis nociceptive behaviors in a dose-dependent manner. Furthermore, the BoNT/A cleaved synaptosomal-associated protein of 25 kDa (cl-SNAP-25) was detected in the DRG using immunofluorescence after intra-articular administration. Although BoNT/A significantly reduced the protein levels of TRPV1, there were no significant changes in the mRNA levels of TRPV1 between CFA and BoNT/A (1U, 3U, 10U) group after BoNT/A retrograde axonal transport into the DRG with quantitative RT-PCR. This research provides evidence that the antinociceptive mechanism of BoNT/A might be mediated by reduction of TRPV1 expression through inhibition of its plasma membrane trafficking after intra-articular administration. [ABSTRACT FROM AUTHOR]

At constant current, the arc voltage increases with increasing helium or CO 2 content. At constant wire feed speed and constant voltage, as the helium or CO 2 content increases, the welding current decreases. The arc length decreases significantly with the increase of CO 2 content and arc core expands with the increase of helium content. When the shielding gas composition changes, arc properties and wire melting characteristics both change and the arc works at a new equilibrium point to keep the wire melting rate equal to wire feed speed. Shielding gas with the addition of helium presents a bowl weld bead profile. The depth of sidewall fusion increases as helium content increases. The welding process and weld quality are good when the shielding gas is 80%Ar10%CO 2 10%He. [ABSTRACT FROM AUTHOR]

Considering the excellent anti-corrosion property in chlorinated mediums and comprehensive mechanical properties of dual phase steel, this kind of steel plate will be widely used in the future. However, when ordinary welding methods are used to weld these steel sheets, large deformation usually occurs during local heating due to the lower stiffness of sheet joints. Based on a thermo-elastic-plastic Finite Element Analysis (FEA) method, considering both material non-linearity and geometric non-linearity, the temperature field and deformation of DP780 steel thin-plate welded joints using Gas Tungsten Arc (GTA) welding and Ultrasonic-wave-assisted Gas Tungsten Pulsed Arc (U-GTPA) welding is simulated. Through the combination of experiment and numerical simulation, the difference in the simulation process for the weld deformation of sheet joints caused by GTA welding with and without acoustic-controlled arc is clarified. In particular, the effects of acoustic-controlled arc and external confining positions on the weld deformation, and residual stress distribution of duplex phase steel joints welded by two welding methods are compared. The research results indicate that the welding heat source of U-GTPA has a smaller acting range on the workpiece and a higher peak temperature (up about 200 °C) than that of GTA. Replacing the traditional GTA with U-GTPA can reduce weld deformation, the maximum buckling deformation of welded sheet is only 4.2 mm and the rate of deformation is reduced by 60%. The numerical simulation confirmed that the high longitudinal tensile stress ranges in U-GTPA-welded joints are narrower than that in GTA-welded joints, but the maximum longitudinal residual stress generated by U-GTPA welding is greater than that generated by GTA welding. Furthermore, the stress distribution in the fusion zone and its surroundings, as well as the out-of-plane deformation of the steel sheet can be further controlled by optimizing the confining positions. The selection of the appropriate restraint positions is also an important factor to the optimization of the U-GTPA welding process. • Dynamic hemispherical heat source is proposed to simulate ultrasonic wave-assisted gas tungsten pulsed arc (U-GTPA) welding process. • Temperature field and deformation of the U-GTPA welded joints of DP780 steel plate are simulated by thermo-elastic-plastic finite element method. • Influences of external restraint position on the welding deformation and the residual stress distribution of U-GTPA welded joints are discussed. • Relationship between the welding residual stress and the out-of-plane deformation of U-GTPA welded joint is revealed. [ABSTRACT FROM AUTHOR]

As a newly developed arc welding method, power ultrasound has been successfully introduced into arc and weld pool during ultrasonic wave-assisted arc welding process. The advanced process for molten metals can be realized by utilizing additional ultrasonic field. Under the action of the acoustic wave, the plasma arc as weld heat source is regulated and its characteristics make an obvious change. Compared with the conventional arc, the ultrasonic wave-assisted arc plasma is bound significantly and becomes brighter. To reveal the dependence of the acoustic binding force on acoustic field parameters, a two-dimensional acoustic field model for ultrasonic wave-assisted arc welding device is established. The influences of the radiator height, the central pore radius, the radiator radius, and curvature radius or depth of concave radiator surface are discussed using the boundary element method. Then the authors analyze the resonant mode by this relationship curve between acoustic radiation power and radiator height. Furthermore, the best acoustic binding ability is obtained by optimizing the geometric parameters of acoustic radiator. In addition, three concave radiator surfaces including spherical cap surface, paraboloid of revolution, and rotating single curved surface are investigated systematically. Finally, both the calculation and experiment suggest that, to obtain the best acoustic binding ability, the ultrasonic wave-assisted arc welding setup should be operated under the first resonant mode using a radiator with a spherical cap surface, a small central pore, a large section radius and an appropriate curvature radius. [ABSTRACT FROM AUTHOR]

Highlights: [•] Pure CeO2 and La doped CeO2 coatings are prepared on Ni based substrates. [•] The emissive property of the coatings at high temperature is investigated. [•] Doped CeO2 coatings show enhanced emissivity with increase in La dopant. [•] The emissivity improvement is ascribed to the free-carrier and lattice absorption. [ABSTRACT FROM AUTHOR]

Background: Muscle spindles (MSs) play a crucial role in proprioception and locomotor coordination. Although the elasticity and viscosity of the extracellular matrix (ECM) within which MSs are embedded may play a key role in MS function, the impact of aging on ECM components is unclear. The aim of the current study was to investigate the age-related physiological changes of the ECM and to verify if these could be due to alterations of the environment directly surrounding MSs. Methods: Hematoxylin Eosin and picrosirius-red staining was carried out; collagen types I (COLI) and III (COLIII) were assessed, and biotinylated hyaluronan binding protein (HABP) immunohistochemical analysis was undertaken to evaluate alterations of the ECM in the intramuscular connective tissue (IMCT) of the hindlimbs of C57BL/6J male mice. Assessments were carried out on 6-week-old (Group A), 8-month-old (Group B), and 2-year-old (Group C) laboratory mice. Results: The capsule's outer layer became progressively thicker with aging (it was 3.02 ± 0.26 μm in Group A, 3.64 ± 0.31 μm in Group B, and 5.81 ± 0.85 μm in Group C). The collagen in IMCT around and within the MSs was significantly higher in Group C, but there were no significant differences between Groups A and B. The MS capsules and continuous IMCT were primarily made up of COLI and COLIII. The average optical density (AOD) values of COLI in IMCT surrounding MS were significantly higher after aging (p < 0.05), but there were no significant differences in COLIII in the three groups (p > 0.05). HA was present in IMCT and filled the MSs capsule. The AOD of HABP of MS showed that there were lower HA levels in Group C with respect to Group A (p = 0.022); no significant differences were noted neither between Groups A and B nor between Groups B and C (p > 0.05). Conclusion: Age-related collagen accumulation and lower HA in the ECM in which the MSs were embedded may probably cause more stiffness in the ECM in vivo, which could help to partly explain the peripheral mechanisms underlying the age-related decline in functional changes related to MSs. [ABSTRACT FROM AUTHOR]

Wire arc additive manufacturing (WAAM) can be used to repair blades or blisk made of titanium alloy with the advantage of high efficiency and low-cost. In this work, the finite element model of repairing the blade based on the arc heat source was established to investigate it. Results showed that the maximum effect of thermal undercooling appeared when the peak current transformed to the base current (1 Hz or 5 Hz), which will promote the grains refinement with the combination of sufficient constitutional supercooling. Compared to the single-layer deposition, the microstructure in the near-heat affected zone (near-HAZ) of multi-layer deposition changes from the metastable β phases to the extremely fine α phases, which was caused by the repeated thermal cycles. [ABSTRACT FROM AUTHOR]

Additive manufacturing of Al-Si alloy thin-walled components with/without interlayer adding La2O3 powder were obtained by cold metal transfer (CMT). Based on the optimisation of the CMT additive manufacturing process, the influences of La2O3 powder on the microstructure and properties of parts were analysed by using OM, SEM and EBSD. The results showed that by adding La2O3, the effective length and layer height of the component was increased due to the increase of the surface tension. Nucleation particles were increased by adding the La2O3, which resulted in that the α-Al and Al-Si eutectic were refined compared with that of no adding La2O3. By adding La2O3, the tensile properties of the part were improved. The refinement microstructure was the main reason for the improvement of mechanical behaviour. [ABSTRACT FROM AUTHOR]

Three nitrogen-rich welding wires with nitrogen content of 0.15 %, 0.6 % and 0.9 % for high nitrogen stainless steel welding were developed by a modified Schaeffler diagram and equilibrium phase diagram calculation. The effect of the chemical compositions especially the nitrogen on the weld defects, element distribution, microstructure, mechanical properties and droplet transfer were studied to evaluate the performance of the welding wires. Nitrogen element in the droplets of nitrogen-rich welding wires was partially lost due to the escape of nitrogen during the welding process, so nitrogen in the welding materials was not completely transported to the weld as designed, resulting in a deviation of actual weld from the design. The joint of the welding wire with 0.6 % nitrogen content had the highest mechanical properties, the tensile strength reached 912.5 MPa, and the impact energy of the weld reached 138.17 J. Full-austenite weld was only obtained in the weld of the wire with 0.15 % nitrogen content, but the tensile strength of the joint was lowest because of the low nitrogen content in the weld. Welding wire with 0.9 % nitrogen content had the most serious nitrogen loss, a few of pores were found in the weld. Moreover, the content of skeleton ferrite in the weld with the welding wire containing 0.9 % nitrogen content was high, resulting in the decrease of the weld impact energy. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether the echo intensity (EI) of the paraneural area (PA), the median nerve (MN) at the carpal tunnel, the EI of the myofascial structure (MS) around MN, the 'PA and MN' at the mid-forearm, and the MN transversal displacement at both sites differs between persons with carpal tunnel syndrome (CTS) and control subjects. Methods: In total, 16 CTS patients and 16 controls, age- and gender-matched, were recruited. Cross-sectional ultrasound images of MN were obtained to evaluate the EI of the PA, the MN at carpal tunnel, the EI of MS, and the 'PA and MN' at the mid-forearm in a natural position, then images were taken after a whole-hand grasp movement, to evaluate MN transversal displacement. Inter-rater and intra-rater reliability in control, and differences in the EI and MN displacement between CTS and control, were analyzed. In addition, the correlations between ultrasound parameters and MN displacement were evaluated. Results: The quantitative EI of PA, MN, EI of MS, 'PA and MN' had high inter-rater and intra-rater reliability in the control. The EI of PA, MS and 'PA and MN' were significantly higher in CTS subjects (p < 0.01), whilst there was no significant difference in the EI of MN at the carpal tunnel. MN displacement was significantly decreased both at the carpal tunnel and the mid-forearm in CTS subjects (p < 0.01). In addition, there were negative correlations among the EI of PA (rs = −0.484, p = 0.004), EI of MS (rs = −0.479, p = 0.002), EI of 'PA and MN' (rs = −0.605, p < 0.001) and MN transversal displacement. Conclusions: The higher EI of PA and MS around MN in CTS may indicate greater fibrosis along the course of MN, reducing fascial adaptability, influencing the synergy and coordination of the MS, and increasing the shear stress between MS and MN, and it may further increase the abnormal pressure on the MN not only at the carpal tunnel, but also at the mid-forearm. These results may partly explain the role of PA and MS in CTS pathogenesis. [ABSTRACT FROM AUTHOR]

(a) Conventional GTAW, (b) U-GTAW, (c) PU-GTAW of 5 Hz and (d) PU-GTAW of 250 Hz. Pulsed ultrasonic assisted gas tungsten arc welding (PU-GTAW) is a newly developed welding method. In this work, the PU-GTAW and un-pulsed ultrasonic assisted gas tungsten arc welding (U-GTAW) was comparative investigated by analyzing the microstructure and mechanical properties of Q235 welded joints. The results showed that the improvement of PU-GTAW on microstructure was more efficient than that of the U-GTAW. The weld seam grain size in the U-TIG and PU-GTAW was refined compared with that of the conventional GTAW. Compared with the conventional GTAW, the change of texture type and the decrease of texture intensity were obtained in the U-TIG and PU-GTAW. The sizes of microstructures in the U-GTAW and PU-GTAW were reduced compared with that of the GTAW, which was caused by the refinement grain. Influence degree of the U-GTAW and PU-GTAW on the hardness of the weld seam was the same. The hardness was increased by about 30HV compared with that of the conventional GTAW. [ABSTRACT FROM AUTHOR]

Peripheral nerve injury (PNI) is a complex clinical challenge resulting in functional disability. Neurological recovery does not always ensure functional recovery, as extracellular matrix (ECM) alterations affect muscle function. This study evaluates hyaluronan (HA) and collagen concentration in the gastrocnemius muscle and thoracolumbar fascia (TLF) in unilateral lower limb PNI rats to explore systemic ECM alterations following PNI and their impacts on functional recovery. Eighteen 8-week-old male Sprague-Dawley rats were divided into experimental (n = 12 left sciatic nerve injury) and control (n = 6) groups. After six weeks, motor function was evaluated. Muscle and TLF samples were analysed for HA and collagen distribution and concentrations. SFI and gait analysis confirmed a functional deficit in PNI rats 6 weeks after surgery. HA concentration in both sides of the muscles decreased by approximately one-third; both sides showed significantly higher collagen concentration than healthy rats (12.74 ± 4.83 µg/g), with the left (32.92 ± 11.34 µg/g) significantly higher than the right (20.15 ± 7.03 µg/g). PNI rats also showed significantly lower HA (left: 66.95 ± 20.08 µg/g; right: 112.66 ± 30.53 µg/g) and higher collagen (left: 115.89 ± 28.18 µg/g; right: 90.43 ± 20.83 µg/g) concentrations in both TLF samples compared to healthy rats (HA: 167.18 ± 31.13 µg/g; collagen: 47.51 ± 7.82 µg/g), with the left TLF more affected. Unilateral lower limb PNI induced HA reduction and collagen accumulation in both the lower limb muscles and the TLF, potentially exacerbating motor function impairment and increasing the risk of low back dysfunctions. [ABSTRACT FROM AUTHOR]

Arc plasma shape under pulsed and continuous ultrasound field was studied in this research using a self-developed welding device which combines arc and ultrasound field coaxially. The results show that, compared with the arc of conventional tungsten inert gas welding, the shape of arc under pulsed power ultrasound field relates to the pulse frequency. From 1 to 20 Hz, the arc plasma expands and contracts periodically in one pulse. When more than 20 Hz, the arc plasma contracts as the pulse frequency increases. During high-pulse frequency, the arc shape becomes steady and similar to those in the continuous ultrasound field. When at 500 Hz, the contraction ratio of arc projected area under pulsed power ultrasound field reaches 38 %, compared with 30 % of the same power continuous ultrasound field; i.e., in high-frequency, low-power pulsed power ultrasound can obtain arc control effect similar to high power continuous ultrasound, raising usage efficiency of ultrasound energy. The mechanism of ultrasonic influence on arc is analyzed based on sound pressure and acoustic streaming. [ABSTRACT FROM AUTHOR]

To form in situ nano-borides in the solid-liquid two-phase region, Ti46 A l8Nb2·6C0.8Ta x B alloys were prepared under ultrasound to improve the microstructural and mechanical properties. The morphology and distribution of borides and the characteristics of lamellar colonies were observed with scanning and transmission electron microscopy and X-ray diffraction; these analyses revealed the influence of borides on microstructural evolution and improved strength and plasticity. The borides that form are elongated and spherical. As the B content increases, the borides gradually spheroidise, and nano-borides precipitate on the lamellar phase. There are a large number of dislocations around the borides to form stacking faults and dislocation walls. The average size of the lamellar colonies decreases from 26.9 to 19.3 μm. The increase in boride nucleation sites as the B content increases and ultrasound-mediate breaking of primary borides are the reasons for forming B27-type borides. The increase in nucleation particles refines the lamellar colony. The compressive strength increases from 2058 to 2299 MPa, and the strain increases from 25.2% to 32.3% when the addition of B increases from 0% to 1.2%. The significantly improved mechanical properties are due to uniformly distributed nano-borides that hinder the movement of dislocations to form stacking faults and dislocation walls and refinement of the lamellar colonies. [ABSTRACT FROM AUTHOR]

This study investigated the connections between the median nerve paraneural sheath and myofascial structures near it, from both macroscopic and microscopic points of view. Four samples of median nerve and surrounding tissues were excised from nine non‐embalmed upper limbs for microscopic analysis. Ultrasound images were analysed in 21 healthy subjects and 16 carpal tunnel syndrome patients to evaluate median nerve transversal displacement during finger motion at carpal tunnel and forearm levels. An anatomical continuity between epimysium and paraneural sheath and a reduction of paraneural fat tissue from proximal to distal was found in all samples. Median nerve displacements at both levels were significantly reduced in carpal tunnel syndrome subjects (P < 0.001). It was observed that the median nerve is not an isolated structure but is entirely connected to myofascial structures. Therefore, unbalanced tension of epimysial fasciae can affect the paraneural sheath, limiting nerve displacement, and consequently this must be included in carpal tunnel syndrome pathogenesis. [ABSTRACT FROM AUTHOR]

The present study compares the structure and composition of fascia lata in healthy subjects and in patients with hip osteoarthritis (OA), to evaluate any differences in the amount of Collagen type I, Collagen type III, and Hyaluronan. Fascia lata samples from voluntary healthy subjects and patients with OA were harvested during surgery. Collagen type I (COL I), III (COL III) antibody, and biotinylated hyaluronan binding protein (HABP) immunohistochemistry stainings were used to evaluate fascial morphology and COL I, COL III, and Hyaluronan (HA) content in both groups. Ten samples from healthy subjects (group A) and 11 samples from OA patients (group B) were collected. COL I was significantly more abundant in the OA group (p = 0.0015), with a median percentage positivity of 75.2 (IQR 13.11)%, while representing only 67 (IQR: 8.71)% in control cases. COL III, with median values of 9.5 (IQR 3.63)% (OA group) and 17.10 (IQR 11)% (control cases), respectively, showed significant reduction in OA patients (p = 0.002). HA showed a median value of 10.01 (IQR 8.11)% in OA patients, denoting significant decrease (p < 0.0001) with respect to the control group median 39.31 (IQR 5.62)%. The observed differences suggest a relationship between fascial pathology and hip OA. The observed increase in COL I in OA patients, along with the reduction of COL III and HA, could lead to fascial stiffening, which could alter fascial mechanics and be linked to the development and symptoms of OA. [ABSTRACT FROM AUTHOR]

Although it is now recognized that women suffer from myofascial pain to a greater extent than men, and that the muscular fasciae can respond to hormonal stimuli, thanks to the expression of sex hormone receptors, how the fasciae can modify their structure under hormonal stimulation is not clear. In this work, an immunocytochemical analysis of collagen-I, collagen-III and fibrillin were carried out on fibroblasts isolated from human fascia lata after in vitro treatment with various levels of sex hormones β-estradiol and/or relaxin-1, according to the phases of a woman’s period (follicular, periovulatory, luteal, post-menopausal phases and pregnancy). This study demonstrates for the first time that fascial cells can modulate the production of some components of the extracellular matrix according to hormone levels, when treated with β-estradiol: collagen-I falls from 6% of positivity in the follicular phase to 1.9 in the periovulatory phase. However, after the addition of relaxin-1 to the cell culture, the production of extracellular matrix decreased and remained at the same level (1.7% of collagen-I, at both follicular and periovulatory levels of hormones). These results confirm the antifibrotic function of relaxin-1, thanks to its ability to reduce matrix synthesis. They are also a first step in our understanding of how some hormonal dysfunctions in women can cause a dysregulation of extracellular matrix production in fasciae. [ABSTRACT FROM AUTHOR]

A concept consolidated in recent years is that tumor growth depends to a great extent on the micro‐environment surrounding the tumor, which has a fundamental role in tumor progression and in determining the effectiveness of therapies. Our analysis focuses on chondrosarcoma, the second primary malignant bone tumor, resistant to both chemotherapeutic and radiation therapy. We quantified hyaluronan, one of the main components of the extracellular matrix, with the aim of comparing its amount in the connective tissue surrounding the tumor with intra‐tumoral tissue and healthy fascia of the same anatomic district, viewed as a health control. We demonstrate that hyaluronan increased significantly in the peritumoral stroma compared with the healthy fascia, which showed an average amount according to the physical characteristics of body districts by a mean value of 26.9 μg/g. In the peritumoral stroma, the mean hyaluronan content reached 132.6 μg/g (mean value of 63.2 μg/g). The p‐value was less than 0.01, showing a highly significant statistical difference. Surprisingly, no significant differences were detected as a function of age, gender, or tumor grade. The levels of hyaluronan were comparable in peritumoral and tumor tissues, although there were differences depending on the state of necrosis. In addition, data on the expression of hyaluronic acid synthetase showed a decrease of about 50% in peritumoral and tumor tissues, indicating alterations in hyaluronan turnover and synthesis. This work demonstrates a variation in hyaluronan contents around the chondrosarcoma, likely correlated with the aggressiveness and resistance to chemotherapy of this tumors. Statement of Clinical Significance: Deeper knowledge about the composition of the peritumoral stroma, rich in extracellular matrix, will enhance better study and understanding of the metastatic potential of tumors and their prognostic indices. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:503–509, 2019. [ABSTRACT FROM AUTHOR]

Purpose: The objectives of this work was to conduct a comprehensive state-of-the art review of the current literature to identify any gaps or discrepancies and summarize the main challenges for obtaining a homogeneous evaluation of muscular fascia in healthy individuals.Methods: An electronic document search using key words and MeSH terms was performed with various databases. Two independent investigators were tasked with the screening of articles and data extraction. A critical appraisal of what is known was then conducted.Results: The literature search identified 65 articles related to healthy facia in the various databases consulted and 20 articles were kept for the review. The thickest portion of the fascia lata (the iliotibial tract) and the plantar fascia are the most often studied muscular fasciae whereas there is paucity of studies on fascia related to other muscles in the body.Conclusion: US imaging is suitable to complement physical examination and for evaluating treatment outcomes. However, the small number of studies and the heterogeneity of the methods did not allow us to establish normal reference values for muscular fascia thickness and to provide strong recommendations about measurement protocols. [ABSTRACT FROM AUTHOR]

The new method named as the pulsed ultrasonic-assisted GMAW (PU-GMAW) is studied in this paper, which was enforced by utilizing the pulsed ultrasonic to control the gas metal arc welding (GMAW) process. The main purpose of this paper is to study the feasibility of pulsed ultrasonic-assisted GMAW. Compared with the continuous ultrasonic-assisted GMAW (CU-GMAW), the influence of PU-GMAW on droplet transfer behavior and weld appearance is discussed. The results showed that the pulsed ultrasonic could assist GMAW. The PU-GMAW and the CU-GMAW both have their own advantages under different evaluation criterions. The droplet transfer cycles of the GMAW, the PU-GMAW, and the CU-GMAW were 199.5, 210, and 222 ms, respectively. The weld pool front angle of GMAW, PU-GMAW, and CU-GMAW are 17.75°, 12.3°, and 10°, respectively. The peak current of GMAW, PU-GMAW, and CU-GMAW were 300A, 350A, and 330A, respectively. Compared with the GMAW, the weld penetration and weld width of the CU-GMAW increased by 100 and 23.6%, respectively. The weld penetration and weld width of the PU-GMAW increased by 86 and 38.2%, respectively. [ABSTRACT FROM AUTHOR]

This study focused on heat-affected zone thermal processes, microstructural evolution, and impact toughness near weld toe of backing passes in double-sided double arc welding where there is stress concentration. The results show that as the arc distance increases, the second peak temperature near weld toe will accordingly decrease and the intercritically reheated coarse-grained heat-affected zone will appear. The formation of martensite-austenite constituents distributed both along the prior austenite grain boundaries and inside prior austenite grains leads to the poor toughness of intercritically reheated heat-affected zone. When short arc distance is adopted, supercritically reheated coarse-grained heat-affected zone will appear near weld toe which possesses high toughness due to the good toughness of lath bainite and the fine bainite/martensite packets. During double-sided double arc backing welding, short arc distance should be used to obtain excellent impact toughness. [ABSTRACT FROM AUTHOR]

In order to improve the plasticity of AlCoCrFeNi high entropy alloys (HEA) without obviously decreasing the strength, Co has been added to this alloy as Co is a FCC phase stabilizer. In this study, the alloying effects of Co addition on the phase types, microstructure and mechanical properties of (AlCoCrFeNi) 100- x Co x are investigated systematically. The result shows that Co element has the capacity to induce phase transformation from BCC phase to FCC phase in the (AlCoCrFeNi) 100- x Co x alloy system, and the volume fraction of FCC phase increases from 0% to 77% as the Co content increases. Compressive testing shows that Co addition has a positive effect in improving the plasticity of AlCoCrFeNi HEA, and the fracture strain increases gradually from 27% to 40%, while the ultimate strength only reduces from 2743 MPa to 2680 MPa as the Co content changes from 0 to 16 at%. The maximum ultimate compressive strength reaches 2974 MPa, while the fracture strain reaches 30%. The increased volume fraction of FCC phase is the main factor in the plasticity increases, and the valence electron concentration (VEC) increase induced by Co addition is the main factor in FCC phase volume fraction increases in this alloy. [ABSTRACT FROM AUTHOR]

This paper aims to reveal the influence of different welding conditions on unaltered coarse grained heat affected zones (UACGHAZs) of backing passes by double-sided double gas tungsten arc welding (DSGTAW) of 10CrNi3MoV steel. UACGHAZs were also compared with coarse grained heat affected zones (GGHAZs) of single gas tungsten arc welding (SGTAW). At lower heat input (21.7 kJ/cm for each run without preheating), CGHAZ mainly consisted of lath martensite (LM) while UACGHAZs composed of LM and small amount of lath bainite (LB). At higher heat input (33.2 kJ/cm for each run with 150 °C preheating), the microstructures of CGHAZ were LM and LB. In UACGHAZs, the microstructures would transform from LB + LM + granular bainite (GB) to LB + GB as arc distance ( d ) decreased. The toughness of UACGHAZs was related to martensite/bainite packet sizes instead of prior austenite grain sizes. At higher heat input, the formation of granular bainite deteriorated the toughness of UACGHAZs and negated the positive effect of LB on toughness. DSGTAW can significantly improve the toughness of coarse grained zones when lower heat input is adopted. [ABSTRACT FROM AUTHOR]

Single-pass multi-layer and multi-pass multi-layer Al–Mg-Zn-Cu alloy components were fabricated by variable polarity TIG-based wire arc additive manufacturing, and the forming and molten pool flow were investigated. The mathematical model of the geometric features of the deposited layers and the deposition parameters was established using the quadratic general rotary unitized design. The layer width and height can be precisely predicted when the deposition parameters are given. The liquid metal flow behaviors in the molten pool were studied by simulation calculation, and the effects of the deposition parameters on the layer width and height were revealed by the analysis of the temperature and flow field distribution. In the multi-pass multi-layer deposition process, owing to the height difference, the more remelted liquid metal of the original deposited metal flows to the side of the layer being deposited under gravity's action, resulting in the separation of the passes. Overlapping with variable distances was proposed to eliminate the separation. [ABSTRACT FROM AUTHOR]

• Energy for electron emission from sheath voltage cannot be identified as heat loss of base metal. • Bypass current affects both the plasma arc physics and heat input of base metal. • The degree of heat transfer decoupling of bypass hybrid arc can be quantified. • Current density and tungsten melting states are the basic reasons for decoupling degree. In this study, we address the influence of bypass current on physical quantities relevant to a hybrid variable-polarity plasma arc (HVPPA). Although bypass current is known to decouple heat transfer, the decoupling effect, which is important for process parameter design, has not been quantified. Therefore, we perform a numerical parametric study at a constant gas flow rate and using a torch structure parameterized by the bypass and plasma arc currents. We develop a coupled transient magnetohydrodynamic finite element model in a three-dimensional face-symmetric configuration implemented in ANSYS FLUENT. The heat flux caused by electronic thermal motion and cathode sheath voltage empowerment of a cold cathode material is established in the modeling of an alternating current arc for the first time. The model reveals that the bypass current influences the temperature distribution of the hybrid arc and total heat flux of the base metal. The degree of heat transfer decoupling of the HVPPA is defined by the heat flux transferred to the base metal, which decreases as the bypass current increases. Moreover, the degree of decoupling differs between the electrode positive and negative phases. This signifies the importance of choosing the current ratio between the plasma and bypass arcs in the metal manufacturing process. The agreement between the fusion lines obtained from the experiment and simulation is analyzed to verify the accuracy of the calculations in this study. [ABSTRACT FROM AUTHOR]

In this paper, the microstructural evolution and mechanical behaviour of the repaired ATI 718Plus sample were investigated in detail. Results show that the deposited zone (DZ) mainly contained columnar grains inclined along the z axis following the steepest temperature gradient during WAAM. And local Nb segregation leads to that a large amount of Laves, η, γ' precipitates gathered in the interdendritic region. In contrast, the substrate zone (SZ) consisted of equiaxed grains and uniform distribution of γ' precipitates. The γ' precipitates in DZ show an obvious height dependence with a trend of increasing with increasing distance from the top to the bottom. Due to the exposure to elevated temperature, grain growth and the dissolution of η, γ' phase were observed in HAZ. The hardness shows a gradual increase along the negative Z axis and an abrupt decrease in HAZ. These significant changes make the HAZ a possible vulnerable region. After direct age (DA) treatment, further growth of η precipitates and sufficient precipitation of γ' phase were observed. The repaired samples always fractured at DZ. The tensile test indicated that UTS in DA condition shows an obvious increase, but the elongation is lower due to the brittle Laves phase acting as stress concentrators in the precipitation-hardened matrix and the fact that only half of the tensile samples experienced obvious deformation. • A defect-free repaired sample could be obtained using wire and arc additive manufacturing. • A gradient distribution of γ' precipitates and mechanical properties were clarified. • The microstructural evolution of the deposited and substrate zones was investigated in detail. • The effect of precipitates on tensile properties under different heat treatments was discussed. [ABSTRACT FROM AUTHOR]

Wire and arc additive manufacturing technology was applied to repair damaged 718Plus components to save life-cycle costs. In this work, the effects of different solution temperatures on the microstructural evolution and tensile properties of repaired samples were investigated in detail. The results showed that the heat-treated microstructure in the deposited zone (DZ) mainly consisted of columnar grains along the building direction. Laves phase, needle-like η phase and γ′ phase were gathered in the interdendritic region. In contrast, the microstructure of the substrate zone (SZ) contained equiaxed grains with grain boundary (GB) η phase and a uniform distribution of γ′ phase. With the solution temperature increasing, the undesirable Laves phase was gradually dissolved, and its morphology varied from long-striped to granular. The number of η phases was observed to increase initially and then decrease with morphology changing to granular. The resultant granular η phase in SZ lost its pinning effect on GBs, leading to the rapid coarsening of grains in SZ. Tensile tests show that the dissolution of Laves phase and η phase in DZ helps to improve the ductility while the grain growth results in the decrease of tensile stress. [ABSTRACT FROM AUTHOR]

A novel bypass coupling variable polarity plasma arc was proposed to achieve the accurate adjusting of heat and mass transfer in the welding and additive manufacturing of aluminum alloy. However, the physical characteristics and decoupled transfer behavior remain unclear, restricting its application and development. A three-dimensional model of the bypass coupling variable polarity plasma arc was built based on Kirchhoff's law, the main arc and the bypass arc are coupled by an electromagnetic field. The model of current attachment on the tungsten electrode surface is included for simulating different heating processes of the EP and EN phases in the coupling arc. The distribution of temperature field, flow field, and current density of the bypass coupling variable polarity plasma arc was studied by the three-dimensional numerical model. The heat input on the base metal under different current conditions is quantified. To verify the model, the arc voltages are compared and the results in simulation and experiment agree with each other well. The results show that the radius of the bypass coupling arc with or without bypass current action on the base metal is different, and the flow vector of the bypass coupling arc plasma with bypass current is larger than the arc without bypass current. By comparing the heat transfer on the electrodes' boundary under different current conditions, it is found that increasing the bypass current results in the rise in heat input on the base metal. Therefore, it is concluded that using bypass current is unable to completely decouple the wire melting and the heat input of the base metal. The decoupled degree of heat transfer is one of the important factors for accurate control in the manufacturing process with this coupling arc. [ABSTRACT FROM AUTHOR]

Abstract: The microstructures and mechanical properties of novel multiphase Nb-based composites from Nb–Ti–C–B system have been investigated. The microstructures were characterized using scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The composites contain Nb solid solution, (Nb,Ti)B boride and (Nb,Ti)C carbide phases. The hybrid (Nb,Ti)B and (Nb,Ti)C together with Nb solid solution form the network microstructure. The composites exhibit high hardness and strength while maintaining desirable fracture toughness at room temperature. Boride and carbide phases effectively improve the strength and hardness of the composites, while Nb solid solution toughens the composites. Higher boron contents increase the hardness and strength, but decrease the toughness. [Copyright &y& Elsevier]

• The diameter and content of ZrO 2 particles have a great influence on the geometry shape and β grain morphology. • The silicides are promoted to form with the addition of ZrO 2. • More silicides tend to precipitate between the heat affected bands (HABands). • The ultimate strength of the multi-layer deposition with 0.5 wt% + 50 nm ZrO 2 was highest, 1116 MPa, which is 100 MPa higher than that of the deposition without ZrO 2 addition. Wire arc additive manufacturing (WAAM) has many advantages of high efficiency and low cost to repair blades or blisk made of titanium alloy. In this work, different contents and sizes of ZrO 2 particles were added in the single-layer deposition and the multi-layer deposition fabricated by the WAAM technology to investigate the microstructure and mechanical properties of the repaired TC17 titanium alloy. Results show that the content and size of ZrO 2 particles have a great influence on the geometry shape and β grain morphology. Especially, the deposition height (d H) increased and the deposition width (d W) decreased with the increased content of 75 µm ZrO 2 under the direct current arc. The silicides are promoted to form with the addition of ZrO 2 , and more silicides tend to precipitate between the heat affected bands (HABands). The addition of ZrO 2 can extremely increase the ultimate strength and make the plasticity meet the standard requirements. Especially, the ultimate strength of the multi-layer deposition with 0.5 wt% +50 nm ZrO 2 was highest, 1116 MPa, which is 100 MPa higher than that of the deposition without ZrO 2 addition. Meanwhile, the strength of the multi-layer deposition with the addition of 1 wt%+ 75 µm ZrO 2 have less of an uplifting effect compared with that of 0.5 wt%+ 75 µm ZrO 2. [ABSTRACT FROM AUTHOR]

• The grains morphology changed with the different solutes particles adding. • The thermal undercooling and the molten pool flows have been found to have obvious effects on the grain morphology evolution. • The influencing factors which affects the grains morphology were discussed in detail. Coarse columnar grains formed during titanium alloy additive manufacturing (AM) are generally regarded as unfavorable, which trend to cause solidification defects and mechanical property anisotropy. Achieving the columnar to equiaxed transition (CET) of grain structures has been a great challenge, especially for wire arc additive manufacturing (WAAM) with the highly localized heat input and large temperature gradient. The interdependence model is widely used to explain and predict the grain size and evolution during the welding or AM process. However, the thermal undercooling and the molten pool flow which were neglect in its assumption have been found to have obvious effects on the grain morphology evolution. In this work, different deposition experiments with the combination of growth restricting solutes (boron), nucleant particles (La 2 O 3), and pulsed arc were employed to investigate these intrinsic factors which are often neglected how to influence the grain morphology. [ABSTRACT FROM AUTHOR]

• Large elongated β columnar grains were inhibited with the addition of Cr particles. • The size of primary α phases was remarkably refined. • The fracture position changed to the far-heat affected zone. Wire arc additive manufacturing (WAAM) provides an efficient and low-cost potential for repairing blades or blisk made of titanium alloy. In this work, three deposition samples were fabricated by pulse arc WAAM for the test of microstructure and mechanical properties with Sn and Cr addition. Results show that the epitaxial growth β columnar grains traversing several deposition layers were formed with the addition of 2 wt% Sn. Large elongated β columnar grains were inhibited with the addition of Cr particles, and several equiaxed grains were formed due to constitutional supercooling of Cr and thermal supercooling of pulse arc. With the addition of 2 wt% Sn and 4 wt% Cr, the size of primary α phases were remarkably refined with the length no more than 2 µm and the width no more than 0.1 µm. The fracture position changed from the deposition zone to the base metal (Far-heat affected zone) with the addition of 2 wt% Sn and 4 wt% Cr compared to the other two depositions. It is of great guiding significance to the repair of TC17 blades or blisk by AM method. Meanwhile, the forming mechanism of two types of microstructure within the weak zone (Far-heat affected zone) and the fracture mechanism were discussed in detail. [ABSTRACT FROM AUTHOR]

Background: In last years the role of fascia in proprioception and pain has been confirmed in numerous papers, but the real structure of fasciae is not still entirely known. To date, many studies have evaluated the elastic fibres in arteries, ligaments, lungs, epidermis and dermis, but only two studies exist about the elastic fibres in the fasciae, and they did not distinguish between superficial (in the subcutaneous tissue) and deep/muscular fasciae. The aim of the study was to assess the percentage of elastic fibres between superficial and deep fascia. Materials and methods: Three full thickness specimens (proximal, middle and distal respectively) were taken from each of four regions of the thigh of three non‐embalmed cadavers: the anterior (Ant), the lateral (Lat), the posterior (Post) and the medial (Med) aspect. Thus, a total of 12 specimens were collected from each analysed thigh and histological Weigert Van Gieson stains was performed. Three sections per specimen were considered for the morphometric analysis. Results: In all the specimens the superficial and deep fasciae were clearly recognizable. The difference in percentage of elastic fibres between superficial and deep fasciae in same region for all four was highly significant (p < 0.001). They are abundant in the superficial fascia than deep fascia. Conclusions: In the light of these findings is evident that the superficial (in the subcutaneous tissue) and deep fasciae have different elasticity. This difference may improve grading of fascial dysfunction in dermatological diseases as burns, scars and lymphedema to better plan treatments. [ABSTRACT FROM AUTHOR]

Gas tungsten arc (GTA) cladding has the advantages of flexibility, low cost, and high quality. AlCoCrFe x Ni (x = 1.0, 1.4, 2.1, 3.0, denoted as S-150, S-160, S-170, S-180, respectively) HEA coatings are prepared by GTA cladding on a low carbon steel substrate using different specific heat input (cladding current). The microstructure and phase structure are investigated by optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM), electron backscattered diffraction (EBSD). The mechanical properties are investigated by microhardness, nanoindentation. The corrosion properties are investigated by open circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The results show that the coating alloys mainly contain an A2 + B2 structure, and the grain boundaries of S-150 are Cr-rich σ phase. With the increase of specific heat input, the grain size becomes larger and the morphology changes from equiaxed to columnar. S-180 displays lower hardness and more active room-temperature creep deformation than S-150, which is attributed to the reduction in grain boundary strengthening, solid solution strengthening, and precipitate strengthening. S-180 displays better corrosion resistance than S-150. The typical corrosion type of S-150 and S-180 is pitting corrosion and intergranular corrosion, respectively This research contributes to the fabrication of large-thickness and large-area corrosion-resistant and wear-resistant HEA coatings. [Display omitted] • AlCoCrFe x Ni (x = 1.0, 1.4, 2.1, 3.0) HEA coatings are prepared by gas tungsten arc cladding. • AlCoCrFeNi HEA coatings have equiaxed and columnar grains with A2 + B2 + σ structure. • The mechanical properties deteriorate as cladding specific heat input increases. • The corrosion types of coatings are pitting corrosion and intergranular corrosion. [ABSTRACT FROM AUTHOR]

The present study compares the structure and composition of fascia lata in healthy subjects and in patients with hip osteoarthritis (OA), to evaluate any differences in the amount of Collagen type I, Collagen type III, and Hyaluronan. Fascia lata samples from voluntary healthy subjects and patients with OA were harvested during surgery. Collagen type I (COL I), III (COL III) antibody, and biotinylated hyaluronan binding protein (HABP) immunohistochemistry stainings were used to evaluate fascial morphology and COL I, COL III, and Hyaluronan (HA) content in both groups. Ten samples from healthy subjects and 11 samples from OA patients were collected. COL I was significantly more abundant in the OA group (p = 0.0015), with a median percentage positivity of 75.2 (IQR 13.11)%, while representing only 67 (IQR: 8.71)% in control cases. COL III, with median values of 9.5 (IQR 3.63)% (OA group) and 17.10 (IQR 11)% (control cases), respectively, showed significant reduction in OA patients (p = 0.002). HA showed a median value of 10.01 (IQR 8.11)% in OA patients, denoting significant decrease (p < 0.0001) with respect to the control group median 39.31 (IQR 5.62)%. The observed differences suggest a relationship between fascial pathology and hip OA. The observed increase in COL I in OA patients, along with the reduction of COL III and HA, could lead to fascial stiffening, which could alter fascial mechanics and be linked to the development and symptoms of OA. [ABSTRACT FROM AUTHOR]

The excellent mechanical and corrosion properties make high-entropy alloys (HEA) be promising structural and coating materials. However, problems like element segregation hinder the fabrication and application of HEA. Ultrasonic melt treatment (USMT) generally has the effect of segregation suppression. In the present study, the impact of ultrasonic treatment on the microstructure, segregation, mechanical properties, and corrosion properties of AlCoCuFeNi HEA coatings prepared by gas tungsten arc (GTA) cladding on low-carbon substrates are examined and discussed. It was found that the coatings with and without ultrasonic treatment both have BCC dendrites and FCC interdendrites. Ultrasonic treatment increases phase fraction of BCC and narrow secondary dendrite arm spacing (SDAS), thereby increasing hardness, elastic modulus, and room-temperature creep resistance. Ultrasonic treatment suppresses dendritic segregation, thereby improving corrosion properties in 3.5 wt% NaCl solution. According to analysis, acoustic streaming has a greater impact compared with cavitation, which accelerates flow velocity and increases the cooling rate. This study preliminarily examines the effectiveness of ultrasonic treatment in suppressing segregation in HEA. [Display omitted] • AlCoCuFeNi high-entropy alloy coatings are prepared by ultrasonic assisted gas tungsten arc cladding. • Ultrasonic increases the phase fraction of BCC and refines microstructure. • Ultrasonic increase microhardness and improve corrosion performance. [ABSTRACT FROM AUTHOR]

Arc cladding high-entropy alloy (HEA) coatings have the advantages of low cost and flexibility. It exhibits economic value to increase the proportion of Fe element in HEA systems. As a result, low-cost AlCoCrFeNi (Fe content of 42.5 at.%, 44.9 at.%, 47.5 at.%, 50.4 at.%) HEA coatings are prepared by gas tungsten arc (GTA) cladding and their microstructure, mechanical properties, and corrosion properties are investigated by XRD, SEM, EBSD, microhardness, nanoindentation, OCP, potentiodynamic polarization, and EIS. The valence electron concentration (VEC) plays an important role in the formation of phase structure. With the increase of Fe content, the phase structure of coating alloys changes from BCC to BCC + FCC, and the morphology changes from equiaxed grains to a dendritic structure. Coating alloy with higher Fe content displays lower microhardness and more active creep deformation due to the higher FCC fraction. The dual-phase (BCC + FCC) structure induces galvanic corrosion and deteriorates the corrosion properties. This work contributes to the fabrication of large-thickness and large-area HEA coatings at a low cost and provides an experimental basis for Fe-rich HEA design. [Display omitted] • AlCoCrFeNi HEA coatings of high Fe content (42.5 at.% ~ 50.4 at.%) are prepared by gas tungsten arc cladding. • As Fe content increases, phases change from BCC to BCC + FCC, morphology changes from granular to dendritic. • As Fe content increase, hardness decrease and corrosion resistance deteriorate. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEA) are promising coating and structural materials for their excellent mechanical and corrosion properties, but the problems like coarse grain hinder the application. Ultrasonic treatment generally has the effect of grain refinement. Therefore, ultrasonic treatment is introduced to the process of gas tungsten arc (GTA) cladding AlCoCrFeNi HEA coatings. It was found that under ultrasonic treatment, the average grain diameter is refined by 70% (from 285 μm to 78 μm). The microhardness is increased by 20% (from 441 HV 1 to 532 HV 1), which is mainly attributed to the Hall-Petch relation. The corrosion performance in 3.5 wt% NaCl solution is also improved and the corrosion type changed from intergranular corrosion to uniform corrosion, which is mainly attributed to the increased segregation of Cr at grain boundaries. The mechanism of the impact of ultrasonic treatment on HEA coatings is discussed based on numerical simulation. Cavitation effect and acoustic streaming play a significant role in the dendritic fragmentation and consequent grain refinement. [Display omitted] • AlCoCrFeNi high-entropy alloy coatings are prepared by ultrasonic assisted gas tungsten arc cladding. • Ultrasonic treatment refined grain diameter by 70%, thereby increasing microhardness by 20%. • Ultrasonic treatment increases segregation of Cr in grain boundaries, thereby improving corrosion performance. • Cavitation effect and acoustic streaming both play a significant role in grain refinement. [ABSTRACT FROM AUTHOR]

It is recognized that different fasciae have different type of innervation, but actually nothing is known about the specific innervation of the two types of deep fascia, aponeurotic and epymisial fascia. In this work the aponeurotic thoracolumbar fascia and the epymisial gluteal fascia of seven adult C57-BL mice were analysed by Transmission Electron Microscopy and floating immunohistochemistry with the aim to study the organization of nerve fibers, the presence of nerve corpuscles and the amount of autonomic innervation. The antibodies used were Anti-S100, Anti-Tyrosine Hydroxylase and Anti-PGP, specific for the Schwann cells forming myelin, the sympathetic nerve fibers, and the peripheral nerve fibers, respectively. The results showed that the fascial tissue is pervaded by a rhomboid and dense network of nerves. The innervation was statistically significantly lower in the gluteal fascia (2.78 ± 0.6% of positive area, 140.3 ± 31.6/mm2 branching points, nerves with 3.2 ± 0.6 mm length and 4.9 ± 0.2 µm thickness) with respect to the thoracolumbar fascia (9.01 ± 0.98% of innervated area, 500.9 ± 43.1 branching points/mm2, length of 87.1 ± 1.0 mm, thickness of 5.8 ± 0.2 µm). Both fasciae revealed the same density of autonomic nerve fibers (0.08%). Lastly, corpuscles were not found in thoracolumbar fascia. Based on these results, it is suggested that the two fasciae have different roles in proprioception and pain perception: the free nerve endings inside thoracolumbar fascia may function as proprioceptors, regulating the tensions coming from associated muscles and having a role in nonspecific low back pain, whereas the epymisial fasciae works to coordinate the actions of the various motor units of the underlying muscle. [ABSTRACT FROM AUTHOR]

Narrow gap TIG welding is a high efficiency and low-cost welding technique for heavy structures building. Due to the narrow groove's constriction, the TIG arc characteristics are different from butt welding. Understanding the unique arc characteristics of narrow gap TIG welding is the foundation for investigating the heat and mass transfer, metallurgic process, as well as process design. This research conducted numerical simulation on the TIG arc plasma in the narrow groove. The effects of welding current and arc length on the arc characteristics are investigated. Results show that, with the welding current increasing, the global velocity magnitude of plasma rises. The evolution of axial velocity and radial velocity has different responses to the current changes. The arc pressure increases drastically, and the global temperature of arc plasma also goes up. With the arc length increasing, global axial velocity rises, but the axial velocity and its gradients decrease near the anode surface. Centripetal radial velocity near the cathode increases, while centrifugal radial velocity rises at the outside of arc plasma and drops near the central axis. The maximum arc pressure on the anode surface decreases. At the lower part of the arc, arc temperature decreases near the central axis and increases at the outside of the arc. [ABSTRACT FROM AUTHOR]

Coarse β-grains and severe surface oxidation are major factors plaguing the comprehensive properties of tungsten inert gas (TIG) welded joints of titanium alloy. To improve the performance of welded joints, a novel current waveform, alternating current/direct current (AC/DC) mixed current waveform which was named Mix-TIG was proposed. In Mix-TIG, the oxide film on the weld surface is broken up by the cathodic crushing effect. Cyclic variations of the current waveform produce stronger arc stirring and more intense oscillations in the molten pool which results in grain refinement. In addition, the lower temperature gradient in the melt pool due to the smaller heat input in Mix-TIG also contributes to grain refinement. The elongation and microhardness of the Mix-TIG were increased. [ABSTRACT FROM AUTHOR]

• A unified numerical model of flexible constrained arc is established. • The annular flexible constrained gas flow can increase arc energy density. • The gas flow constrained arc causes eddy at small arc lengths, easily leading to electrode contamination. • The gas flow constrained arc can effectively inhibit metal vapor backflow. Energy dispersion and easy instability associated with arcs, the traditional metal processing heat source, restrict its development and application in the modern high-precision welding and additive manufacturing. This work aims to study the characteristics of a novel arc under circumferential gas constraint effect which can improve the arc stability and processing accuracy. A magnetohydrodynamics model was established to calculate the arc physics and heat transfer, considering the electron emission characteristics of tungsten and the effect of metal vapor. It indicates that the annular flexible constrained gas flow can significantly increase the physical characteristics such as arc temperature, plasma flow velocity and current density compared with traditional free arc which is named GTA. The arc heat generation increasement of the novel arc makes the heat transfer from arc to base metal higher than that of GTA. The additional annular gas flow inhibits the diffusion of metal vapor, stabilizing the arc and protecting the tungsten electrode from contamination. However, as the arc length decreases, eddy of arc plasma flow appears inside the arc, which can cause metal vapor to contaminate the tungsten. It's found that this novel gas flow constrained arc needs to be applied with a small current when welding with small arc length to avoid the eddy. Finally, the accuracy of the calculation model is verified by experimental detection of arc temperature. [ABSTRACT FROM AUTHOR]

Although the number of Ultrasound (US) imaging studies investigating the fascial layers are becoming more numerous, the majority tend to use different reference points and terminology to describe their findings. The current work set out to compare macroscopic and microscopic data of specimens of the fascial layers of the thigh with US imaging findings. Specimens of the different fascial layers of various regions of the thigh were collected for macroscopic and histological analyses from three fresh cadavers and compared with in vivo US images of the thighs of 20 healthy volunteers. The specimens showed that the subcutaneous tissue of the thigh is made up of three layers: a superficial adipose layer, a membranous layer/superficial fascia, and a deep adipose layer. The deep fascia is composed of an aponeurotic fascia, which envelops all the thigh muscles and is laterally reinforced by the iliotibial tract and an epimysial fascia, which is specific for each muscle. The morphometric measurements of the thickness of the superficial fascia were different (anterior: 153.2 ± 39.3 µm; medial: 128.4 ± 24.7 µm; lateral: 154 ± 28.9 µm; and posterior: 148.8 ± 33.2 µm) as were those of the deep fascia (anterior: 556.8 ± 176.2 µm; medial: 820.4 ± 201 µm; lateral: 1112 ± 237.9 µm; and posterior: 730.4 ± 186.5 µm). The US scans showed a clear picture of the superficial adipose tissue, the superficial fascia, and the deep adipose tissue, as well as the deep fasciae. The epimysial and aponeurotic fasciae of only some topographic areas could be independently identified. The US imaging findings confirmed that the superficial and deep fascia have different thicknesses, and they showed that the US measurements were always larger with respect to those produced by histological analysis (p < 0.001) probably due to shrinkage during the processing. The posterior region (level 1) of the superficial fascia had, for example, a mean thickness of 0.56 ± 0.12 mm at US, while the histological analysis showed that it was 148.8 ± 33.2 µm. Showing a similar pattern, the thickness of the deep fascia was as follows: 1.64 ± 0.85 mm versus 730.4 ± 186.5 µm. Study results have confirmed that US can be considered a valid, non‐invasive instrument to evaluate the fascial layers. In any event, there is a clear need for a set of standardised protocols since the thickness of the fascial layers of different parts of the human body varies and the data obtained using inaccurate reference points are not reproducible or comparable. Given the inconsistent terminology used to describe the fascial system, it would also be important to standardise the terminology used to define its parts. The difficulty in distinguishing between the epimysial and aponeurotic/deep fascia can also impede data interpretation. [ABSTRACT FROM AUTHOR]